Target Exam

CUET

Subject

Biology

Chapter

Sexual Reproduction in Flowering Plants

Question:

Read the passage carefully and answer the questions based on the passage:

Pollen pistil interaction involves all events from the landing of pollen grains on the stigma until the pollen tube enters the embryo sac (when the pollen is compatible). When a pollen tube grows through the style and enters into the ovules, it finally discharges two male gametes in one of the synergids. Syngamy and triple fusion are two fusion events occur in angiosperms. Thus, angiosperms exhibit double fertilization. The products of these fusions are the diploid zygote and triploid primary endosperm nucleus. Zygote develops into embryo and primary endosperm cell forms the endosperm tissue. The developing embryo passes through different stages before maturation.

Formation of diploid zygote is a result of:

Options:

Emasculation

Triple fusion

Syngamy

Bagging

Correct Answer:

Syngamy

Explanation:

The correct answer is Option (3)- Syngamy

Explanation:

  • Syngamy refers to the fusion of the male gamete (sperm, haploid) with the female gamete (egg, haploid) to form a diploid zygote (2n). This is a key event in sexual reproduction.
  • Emasculation is the removal of stamens from a flower to prevent self-pollination (used in plant breeding).
  • Triple fusion is the fusion of one sperm cell with two polar nuclei in the embryo sac to form the triploid primary endosperm nucleus (3n), which develops into the endosperm.
  • Bagging is a technique used to cover emasculated flowers to prevent unwanted pollination.